Preparation of thin film capacitors has generally required that an insulating free standing dielectric film be sandwiched between thin metal foils. The dielectric film and metal foil have then been spirally wound together to produce a device. One major disadvantage of this technique has been that metal foils use a large percentage of the available weight and volume in the fabricated device. Since energy capacity of the device is directly related to surface areas of insulating dielectric, a reduction in the volume of the contact through use of vanishingly thin, conductive polymeric films should increase the energy capacity of the resulting device. In addition, since the density of conducting polymers are generally between 1 and 1.5 g/cm while aluminum is 2.7 g/cm , a substantial reduction in energy capacity per unit weight can also be realized. Therefore, if an insulating dielectric can be readily placed on a thin conductive material, this would be of great interest.
Another major disadvantage of the standard technique has been that pinholes in the insulating dielectric can have catastrophic effects on the resulting device. That is, when the capacitor is stressed with a high voltage and a pinhole is present, a tremendous current density passes through the pinhole causing heat generation and subsequent deterioration of the insulating dielectric. However, if the conductor were a conducting polymer, heat build-up from the current would quickly flash off the conducting polymer, shut off the current and isolate the pinhole. This self-healing process from pinholes would also be of great interest.